New capabilities of standard of volumetric water content of oil and oil products

The last decade has shown major changes in the field of oil production and processing: the necessity of commercial accounting of produced oil with high water content (water content over 90%); the development of on-stream moisture meters with new operating principles, moisture meters with measurement range of volumetric water content from 0 to 100% including meters of foreign manufacture; the measurement accuracy increase of on-stream moisture meters. The work features an overview of the existing methods and instruments for the measurement of volumetric water content of oil and oil products. It is shown that working measuring instruments operate in the volumetric water content range of 0 ÷ 100%, while the State verification schedule and State special standard GET 87-75 provide transfer of the unit up to 60% of the operating range only. Due to this, the necessity has arisen for the improvement of State primary special standard of unit of volumetric water content of oil and oil products. As a result of the performed works, a new process system has been developed, consisting of a hydraulic circuit, measuring instruments for parameter determination of original components of oil-water mixtures, a facility for deep drying of oil, devices and auxiliary equipment providing refinement of the created mixture and maintenance of internal environment in the standard room. Reproduction of the unit of volumetric water content by the standard is based on the method of creating a water-oil mixture with set water content by means of precise proportioning of components and creation of an equal-part mixture on their basis. The proportioning is performed in mass fractions; the transition from mass to volume fractions is performed on the basis of predetermined parameters of original components of the mixture (density, original water content, salt content). As a result of the conducted research, metrological characteristics of the new standard have significantly improved; the possible sources of additional error have been identified and minimized. The new standard GET 87-2011 approved by Rosstandart order No. 252 features improved metrological characteristics and provides reproduction of the unit of volumetric water content within the range of (0,01 ÷ 99,9%).